Anything you charge to your room you can pay off with Disney gift cards! Just make sure to go to the front desk once a day to pay down the charges, otherwise they may run the charges on your credit card after a day or two and you get to the night before check-out and the front desk says "we already charged your credit card". (And if the CM checking you in says you can do it the night before check-out do not listen. They are wrong.)
(Yes, I have an unfortunate story but at the end it worked out. Even if they charge your credit card you can get the charges reversed and pay with gift cards, it's just a real pain. Admittedly I had an overly lazy CM, or maybe they were scared of their manager? idk, on my last night when I went to pay my account at DLH. I kept saying I want to pay with my gift card and his response kept being "sorry, we already charged your credit card" like he thought I'd totally just go "oh, ok" and walk away? I actually had to demand he get a manager. Usually something wonky like that happens and the CM would just go get someone higher up the food chain on their own... Anyways about 45 mins later a manager got the charges reversed, while having the gall to chide me about how this is how their system works -uh, lady YOUR CM at the check-in desk told me it worked differently now- and they finally charged my gift cards but save yourself the hassle- pay off your room account with gift cards each evening!) So, apparently that late night episode from last year's trip is still bothering me...
In much more useful information OP, are you using disneygiftcard.com to combine your gift cards? You can put up to $1,000 on each gift card.